This invention concerns a cycloheximide resistant gene, a process for producing the same, a recombinant DNA vector containing the resistant gene and a transformant containing the resistant gene.
It has been known that cycloheximide is an antibiotic which inhibits the protein synthesis of various eukaryotes by binding to the subunit proteins of 60S (precipitation constant) ribosome.
On the other hand, mutation changing the cycloheximide sensitivity of ribosome has been reported in several eukaryotes up to now.
Although wild-type Saccharomyces cerevisiae is sensitive to cycloheximide, several cycloheximide resistant variants have been isolated. For example, it has been shown that a change in the structural gene coding the ribosome protein causes the cycloheximide resistance and cyh2 variant (Walter Stockleim and Wolfgang Piepersberg, Current Genetics, 1, 177-180 (1980)).
Further, wild-type Kluyveromyces fragilis itself, a yeast, is cycloheximide resistant. In this case, it has also been demonstrated that the ribosome protein is not sensitive to cycloheximide.
These data suggest that the cycloheximide resistance is determined by the structure of several genes coding for the ribosome protein, in addition to the resistance acquired due to the change in the membrane permeability of chemicals as discussed by Adoutte-Panvier and Davies, Mol. Gen. Genet. 194, 310 (1984).
In view of the above, there has been a demand for the gene rendering the ribosome protein resistant to cycloheximide and providing for the protein synthesis free from cycloheximide inhibition for the protein synthesis.